Media monitoring systems typically include one or more device meters to monitor media presented by one or more media devices located at one or more monitored sites. In some examples, the device meters employed by the media monitoring systems use watermarks (also referred to as codes) decoded from the presented media, and/or signatures (also referred to as media fingerprints or just fingerprints) generated from the presented media, or both, to monitor (e.g., identify and/or track) the media being presented by the monitored media devices. Some media monitoring systems further employ media device activation detectors (also referred to as on/off detectors) to detect whether the monitored media devices are active (e.g., turned on) or inactive (e.g., turned off) to verify whether the decoded watermarks and/or generated signatures actually correspond to media presented by the media devices.
Wherever possible, the same reference numbers will be used throughout the drawing(s) and accompanying written description to refer to the same or like parts, elements, etc.